1. Field of the Invention
This invention relates to an electronic apparatus, and, more particularly, it is concerned with an electronic apparatus such as, for example, a recording type electronic desk calculator provided with a roll of recording paper and a recording means using a ball-point pen (i.e., a recording member having ink contained therein).
2. Description of the Prior Art
One example of the conventional electronic apparatus having a recording means utilizing the ball-point pen is illustrated in FIGS. 1 to 4 of the accompanying drawing.
In FIGS. 1 and 2, a reference numeral 1 designates a main body of the electronic apparatus, which is composed of an upper casing 1a and a lower casing 1b to be fitted and fastened together by threaded bolts etc. Within this main body 1, there is placed a printing device to be described later.
The top surface of the upper casing 1a has a power source switch 2 and a button key 3 to perform various controlling operations of the printing device, all of them being electrically connected with an operational circuit disposed inside the main body 1.
A reference numeral 4 denotes printing paper which is wound in a roll form. The forward end of the printing paper is led out of an opening part formed in a cover 5 provided in a detachably attachable manner on the top surface of the upper casing 1a.
A paper cutter 7 appears at the opening part 6 to enable the printing paper 4 to be severed at any arbitrary position.
At the near side of the main body 1, there is provided an arm 8 formed of a metal rod, etc. which extends along the main body 1 and is bent at both end parts. The roll of printing paper is rotatably supported on this arm 8.
FIGS. 3 and 4 illustrate the printing device to be housed in the main body 1.
In the drawing, the printing device 9 is assembled in a rectangular frame as the base: a guide bar 11 is laterally extended between a pair of side walls of the frame and a carriage 10 is slidably fitted on this guide bar 11. The carriage 10 is reciprocally driven in the horizontal direction by a pulse motor 12.
Further, a platen 13 is rotatably provided in parallel with the guide bar 11, one end of which platen has a gear 14 fixed thereon outside the frame. The gear 14 is meshed with a pinion gear 14b fixed on the output shaft of another pulse motor 15 through an intermediate gear 14a. A pair of pinch rollers 13a, 13a are disposed at both end parts of the platen 13. The abovementioned printing paper 4 is led out of a clearance between the platen 13 and the roller 13a, passing underneath the platen 13.
By the way, a ball-point pen 16 as the recording means is mounted on the carriage 10, and the rear end part 16a of the pen is in contact with the top end part of a hammer 19. The bottom end part of the hammer 19 is axially supported on a shaft 18 in a rotatable manner, and is oscillated by a solenoid 17 mounted on the side surface of the frame.
On the other hand, a return spring 20 which is bent in an L-shape with its one side being directed upward is provided on the carriage 10 to the side of the platen 13. This upright portion has a small perforation formed in one part of it, through which passes the front distal end 16b of the ball-point pen 16 confronting to the platen 13.
In the electronic apparatus having the construction as described above, when the printing signal is applied to the solenoid 17, the hammer 19 is rotated clockwise with the shaft 18 as the center of its rotation as shown by an arrow a in FIG. 4, and pushes the rear end of the ball-point pen 16. On account of this, the ball-point pen is pushed forward in the direction of an arrow b against the resilient force of the return spring 20 to thereby perform the dot printing on printing paper wound on the platen 13. As soon as electric conduction to the solenoid 17 is interrupted the ball-point pen 16 returns to its original position by the force of the return spring 20. In this manner, the printing operations are sequentially carried out.
FIG. 5 illustrates another example of the holding structure for the printing paper 4, in which a set of supporting plates (or brackets) 21, 21 are projectively provided on the rear surface side of the main body 1. The mutually opposite surfaces of the supporting plates 21, 21 each has a U-shaped bearing 21a formed thereon, and a shaft 22 for the printing paper 4 is supported on this bearing 21a in a freely rotatable and detachable manner. The shaft 22 is inserted into the center hole 4a of the roll of printing paper 4. It is thus possible to rotatably support the rolled printing paper 4 by the use of such construction as mentioned above.
However, in the electronic apparatus having the recording means using the ball-point pen as mentioned above, there is such an inconvenience that, since the tip of the ball-point pen is, as a matter of course, exposed to the external air during its use, the ink tends to solidify and clog the pen, if the tip end of it is left exposed to the external air while it is not in use.
As the measures against such solidification of ink, therefore, it has heretofore been a practice with the conventional device that the ball-point pen 16 is removed from the carriage 10 and the tip end part of the pen is covered with a cap. This involves an extremely complicated procedure, and, moreover, it happens frequently that the ball-point pen 16 of a relatively small size and of a special design is lost due to its being left somewhere and forgotten. Further, some numbers of spare ball-point pens are usually reserved not only in anticipation of its missing, but also in preparation for ink exhaustion. In most cases, however, these spare ball-point pens are stored in a separate place from the electronic apparatus, as in a desk drawer, etc.. Taking into further consideration out troubles in finding out such small piece of the missing ball-point pen, therefore, the exchanging operation of the ball-point pen, in conjunction with the abovementioned removal of the ball-point pen from the carriage and capping of its distal end, becomes far more complicated.